Method for producing a pallet-less packaging unit and a packaging unit produced according to the method

ABSTRACT

A method for producing a pallet-less packaging unit has multiple packaging objects stacked to a stack of goods. The objects are stacked with a special layer that forms at least two encroachment areas for fork legs of a lift truck in at least one stack level. The special layer is first stacked on a normal layer larger than the special layer. The stack of goods is wrapped with its encroachment areas with a first film, the stack of goods that is wrapped on one side is turned around so the part of the stack of goods that has the special layer comes downwards and the stack of goods is wrapped with a second film that reaches up to the first film. In embodiments, second encroachment areas extend essentially at a right angle to first encroachment areas. The method provides a pallet-less packaging unit that can be handled more easily.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. § 119 to European patent application 16 194 389.9, filed Oct. 18, 2016, the entire disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a method for producing a pallet-less packaging unit that comprises several packaging objects stacked to a stack of goods and in which the packaging objects are stacked in a way that at least two encroachment areas for fork legs of a lift truck are formed on at least one stack level, that the stack of goods is wrapped at least with its encroachment area with a first film, that the stack of goods wrapped on one side is turned around so that the part of the stack of goods that has the encroachment areas comes downwards and that the stack of goods is wrapped by a second film that reaches up into the encroachment areas. The present invention relates to a method with the general features as described herein.

BACKGROUND

Such a method is known from the DE 26 14 558 and DE 27 02 613 that can be traced back to the present applicant. In this previously known method, a shrink hood is pulled over the stack of goods as a first film that is subsequently fitted tightly to the stack of goods by means of thermal shrinking under welding with a further plastic film that was previously laid onto the stack of goods. After turning, a further shrink film hood is pulled over the stack as a second film and also shrunk onto the stack by means of thermal shrinking under welding with the overlapping areas of the first film.

The method according to this type has proven to be effective in particular for forming packaging units of stacked bags, for example bags with petrochemical products, fertilizers, cement, gypsum or mortar products, i.e. in particular in such areas where the use of pallets for storing a stack of goods is unusual and/or the return or use of pallets after unloading of the packaging objects is omitted.

However, also in case of the previously known method there is something left desire, specifically in relation to handling of the packaging unit. While pallet-less packaging units used to be handled in isolation as piece items, they are nowadays usually transported in containers. For filling of the containers as compactly as possible with the packaging units, there is the need to arrange the packaging units in the container in a particular way and with a specific orientation in relation to one another.

SUMMARY

The present invention seeks to indicate a method that is suitable for the production of packaging units made in a pallet-less way as well as a packaging unit that is packaged accordingly in a pallet-less way and that can be handled in an improved manner.

To solve the problem, it is suggested with regard to the method to form the first special layer with two first encroachment areas that are formed and disposed in a way as to be adapted to the encroachment of two fork legs of a lift truck. In addition, the special layer forms two second encroachment areas for the fork legs that extend at a right angle to the first encroachment areas and that are formed in a way as to be adapted for the encroachment of the fork legs of a lift truck. The packaging unit produced according to the method is, as usually preferred, a packaging unit with a rectangular base area. Hence, the first encroachment areas extend in a first direction and the second encroachment areas in a second direction that essentially extends at a right angle to said first direction.

The packaging unit indicated with the present invention correspondingly has two first encroachment areas of the aforementioned type and two second encroachment areas of the aforementioned type, wherein the first and the second encroachment areas are provided and extend in a rectangular arrangement towards one another. Hence, a lift truck that handles the packaging unit can drive into the encroachment areas with its fork legs from two directions that are shifted by 90° in relation to one another and lift the stack of goods and subsequently maneuver it. This way, for example stacks of goods with a different orientation in relation to one another can be arranged in a container.

Common stacks of goods regularly have a rectangular and not a square-shaped layout with a base area that has a width of approximately 1100 mm and a length of approximately 1300 mm. the description of the present invention preferably relates in this context to packaging units that are formed of bags filled with bulk material. Even though the delineation that forms the bag can usually be prepared in a tailored way, there is a certain variation of the dimensions as well as of the weight of the bags filled with bulk material due to the bulk material that is absorbed by the bag. Hence, all details regarding dimensions and weights of the bags that are mentioned in this description shall be understood with a certain tolerance. Modern scales can determine nearly the exact net weight for a bag with a high accuracy and velocity. Hence, the indicated weights shall be understood with an inaccuracy of approximately 2%. With regard to the dimensions, higher inaccuracies shall apply, which can be determined by the morphology and/or grain size distribution and/or the tare weight of the bulk material. Hence, the details regarding the dimensions shall be understood with an inaccuracy of up to 10%, preferably up to 5%.

The material that forms the first and second film can be a shrink film by means of which the stack of goods is at first wrapped in an essentially tension-less way. Subsequently, the tubular film is heated through the application of heat in a way that the orientations of the molecule chains, which have been frozen during production of the film, relax, wherein the dimensions of the film shrink as it is generally known from the state of the art DE 26 14 558 and DE 27 02 613 described before.

Alternatively, the first and/or second film can also be formed by a stretch film as it is known for example from the EP 2 036 818 A1 that can be traced back to the applicant. The particularities for the formation of a stretch film formed of a tubular film indicated therein can also be applied in the present method. This is particularly true for the feeding of material of the second film so that said film ends at the level of the encroachment areas and is actively liberated for example by means of driving crimping rollers in order to push film material, which is located in the area of the encroachment areas, in an inward direction and to lay said material essentially onto the contour of the stack of goods and onto the areas that surround the encroachment areas as it is known from the EP 2 036 818 A1.

In the method according to the invention and in the packaging unit according to the invention, the encroachment areas are usually provided in a horizontal position that is formed by a single layer of packaging objects. In case of a stack of goods that is formed of bags, several bags are located accordingly on one level for the formation of the special layer. For the formation of the encroachment areas, This special layer is usually covered throughout its overall circumferential area by the normal layer located on top of it. During stacking of the stack of goods, the one that is usually the last layer is laid accordingly as a special layer in a central way and with a lateral distance to the side areas of the cuboid-shaped part of the stack of goods that has been stacked up to then. The special layer therefore has an appropriate distance to the encroachment of the fork legs of a lift truck towards each edge of the side area.

In particular during stacking of a stack of goods consisting of filled bulk material bags it has proven to be effective to arrange said bags in a way that encroachment areas are formed. This is implemented in the state of the art by using identically formed bags in case of a different arrangement of the bags in the special layer for a reduced number of bags. According to a preferred embodiment of the present invention, however, it is suggested to form the packaging units of the special layer smaller than the packaging units of the normal layer. Smaller means in this context that the dimensions of the packaging units in the top view onto said units are smaller for the packaging units of the special layer than for the packaging units of the normal layer. The top view is in this case a top view onto the base area of the bags lying on a level so that the main side area of the bags is visible.

The packaging units forming the special layer have the same size in the context of the tolerance to be recognized during production of packaging units. Also, they preferably have the same weight and in particular have a net weight of approximately 18.75 kg. Preferably, four bags are unified as packaging units in the special layer and for the formation of said special layer. The normal layer located on top usually has five packaging units. The five piece item bags that preferably form the normal layer usually have a weight of 25 kg.

While maintaining the otherwise known dimensions for piece item bags with a width of 440 mm and a length of 650 mm, it has proven to be advantageous to form the special layer of packaging objects, preferably bags, that have a corresponding base area of 440 mm+/−30 mm, preferably +/−15 mm, in width and 510 mm+/−30 mm, preferably +/−15 mm, in length. In this context, the preferably four packaging units are preferably joined to a rectangle which leads to a special layer with a base area of 880 mm+/−60 mm, preferably +/- 30 mm, in width and 1020 mm +/−60 mm, preferably +/−30 mm, in length. The normal layer, which is usually located on top, is spread out by five common bags with a base area of approximately 1100 mm, i.e. 1100 mm+/−60 mm, preferably +/−30 mm, in width and approximately 1300 mm, i.e. 1300 mm+/−60 mm, preferably +/−30 mm, in length. All layers except the special layer are usually provided with this dimension. However, the bags are stacked up in successive layers and in a shifted way in relation to one another in order to achieve the best possible grouping of the bags.

According to a preferred further development of the present invention, bags with a different length are produced and filled at a bagging facility. In this procedure, bags with a different size are produced on an identical bagging facility. This bagging facility communicates with a stock of bulk material to be bagged. In the bagging facility, the bags to be filled are usually made of an identical inserted tubular material and at first closed with a lower transversal welding seam, then filled and subsequently sealed with an upper transversal welding seam in order to enclose the bulk material in the bag (form-fill-seal method). The bags produced this way are dropped on a conveying track and fed to a palleting device in which the bags are stacked up as packaging units into a stack of goods. During production of the bags by means of the form-fill-seal method, the same film material is preferably used, which leads to a simplified procedure.

The bags can thereby be fed respectively from the bagging facility to the palleting device in the quantity and order required for stacking of the overall piece item stack. If we assume that the stack of goods has eleven normal layers and one special layer, 55 bags of the normal layer and subsequently four bags of the special layer are produced, filled and fed to the palleting device accordingly for stacking of a stack of goods in one cycle.

The arrangement of the bagging facility, conveying track and palleting device is known as such in the state of the art. In the state of the art, there is usually a control device, which is formed suitably to identify and to eliminate unusable bags, i.e. to discharge said bags from the conveying track so that they will not be fed to the palleting device, between the bagging facility and the palleting device. Unusable bags are for example bags that are not sealed reliably. For this purpose, the control device can detect bulk material that is trickling out of the bag and discharge the respective bag. Likewise, a metal detector can identify bags that contain metallic foreign objects. Hence, bags with plastic granulate are usually discharged when they contain metallic foreign objects.

In terms of data, such a control device can be coupled to the bagging facility in order to replace the respective discharged bag without the desired sequence of smaller bags and larger bags for stacking the special layer and the normal layer of the cycle being disturbed. Accordingly, the bagging facility can produce and fill bags of different sizes in the cycle in which the respective sequence of bags of different sizes is required for stacking the stack of goods. Only the discharge of a bag explains the need for replacement that is satisfied immediately by the bagging facility.

Alternatively, the bagging facility can feed bags of different sizes to the palleting device via different conveying paths so that the bags are kept ready for the special layer at a place in the area of the palleting device and for the normal layer at another place. Hence, the bags that are provided for the normal layer are used for stacking the normal layers. The other conveying track is used for placing the special layer.

In this process, the stack of goods can be stacked at a single palleting position. Stacking can occur with a device as it is for example described in EP 2 258 618 B1. Any other conventional palleting device for stacking the bags is also suitable.

Alternatively, the bags of the normal layer can be stacked at a first palleting position in the palleting device at first, which is generally the case. From there, the stack of goods, which is not yet completed, can be conveyed away out of the first palleting position and preferably via a conveying track with a drive for moving the stack of goods until said stack is lifted off the conveying track. At a second stacking position, positioning of the special layer takes place by means of a laying device for the special layer. This device can be formed by a robot or another handling mode. Due to the procedure described before, the requirement for immediate subsequent conveying of faulty bags for completing the cycle of small and large bags during discharge of said faulty bags can be omitted, which can in particular be problematic in cases where the faulty bag occurs immediately after a change, for example when the faulty bag is one of the regular four smaller bags of the special layer but the device has already started to produce a sequence of bags of the normal layers. In view of this, it is preferable to drop a plurality of bags of the special layer in a storage facility that is used for forming the special layer. In the same way, the bags of the normal layer are dropped in a storage facility. The device for performing the method detects a bag that is discharged as faulty and determines the replacement requirement on this basis. The storage facility is refilled accordingly so that a sufficient number of bags for stacking the stack of goods are always kept ready at any time.

According to a preferred embodiment, the present invention provides a method in with bags with different sizes are produced and filled in a bagging facility, which stacks to bags as packaging units to a stack of goods, and fed to a palleting device via a conveying track. More preferably, the palleting device stacks the bags of the normal layer and the bags of the special layer at a palleting position.

Further, and according to a preferred embodiment of the present invention, the pallleting device stacks the bags of the normal layer at a first palleting position and that the bags of the special layer are laid via a laying device of the special layer.

Still further, and according to a preferred embodiment of the present invention, the bags of the normal layer and the bags of the special layer are made of the same film material by means of a form-fill-seal method.

The aspects specified in the last three paragraphs of the present invention may per se be substantial for the invention in isolation. Hence, the presently described invention can also be seen in that bags with different sizes can be produced successively, preferably in alternating sequences, and fed to a palleting device in one single bagging facility. A cycle can comprise the production of 40 to 140, preferably up to 60 large bags of the normal layer, followed by 3 to 20, preferably up to 6 small bags of the special layer. Multiple cycles are usually performed in a row. With regard to the desired sequence of smaller and larger bags, the device also comprises a storage facility that counts all the dropped bags and therefore processes the data collected in this process in a way that the control of the device records data that it can retrieve and that knows the number of the bags with different sizes in the area of the buffer and/or storage facility behind the bagging facility and/or directly ahead of the palleting device and that can output said data for the process control.

The present invention furthermore provides a packaging unit with several layers of packaging objects that are stacked on top of each other in a way that encroachment areas for fork legs of a lift truck, on which a normal layer is placed that is larger in relation to the special layer, are formed in a stack level by a special layer, with a hood made of a first film material, which wraps a top side and at least parts of the side areas of the packaging unit, and a hood made of a second film material, which is pulled over the stack of goods in the opposite direction to said hood made of a first film material, wherein the special layer forms two first encroachment areas for the fork legs and two second encroachment areas for the fork legs, wherein the second encroachment areas extend essentially at a right angle to the first encroachment areas.

According to a preferred embodiment of the present invention, packaging objects are bags filled with bulk material.

BRIEF DESCRIPTION OF THE DRAWINGS

Further details and advantages of the present invention can be taken from the following description of an embodiment of the present invention in connection with the drawings. The following is shown:

FIG. 1 generally illustrates a top view of a normal layer of the embodiment;

FIG. 2 generally illustrates a top view of a special layer of the embodiment;

FIG. 3 generally illustrates a top view from above onto the stack of goods with the outer contours of a normal layer and the dashed contours of a special layer that are located underneath; and

FIG. 4 generally illustrates a side view of a fully wrapped stack of goods comprising a special layer and a plurality of normal layers.

DETAILED DESCRIPTION

FIG. 4 shows an embodiment of the stack of goods 2 with multiple packaging objects 4 that are grouped together in respectively one stack level and that should be formed in the present case by bags filled with bulk material. Multiple layers of packaging objects 4 are stacked on top of each other. Each stack level has the same number of packaging objects 4 in the normal layers 5 so that an essentially cuboid-shaped stack of goods 2 is formed. Only the layer that is at first stacked at the top is formed as a special layer 8 and has fewer packaging objects 10. During stacking of the special layer 8, said special layer is stacked at an omnidirectional distance to side areas marked with reference sign 12 of a cuboid that is formed by the normal layers 5.

The stack of goods 2 formed this way is coated in a counter hood method in a way that is known in principle as can be read from the EP 2 036 818 A1 and/or EP 2 248 722 A1 that can be traced back to the applicant. According to this method, the special layer is located at the very bottom and forms encroachment areas below the lowest normal layer 5.1 that are marked in FIG. 3 with first encroachment areas 14 and second encroachment areas 16. The encroachment areas have approximately one identical cover. Accordingly, the last normal layer 5.1 extends beyond the special layer 8 with approximately the same overhang at all circumferential areas.

A stack of goods 2 formed this way is formed with a special layer 8, which is shown in FIG. 3, in this embodiment. It consists of four piece item bags 10 with a respective length L of 510 mm and a width B of 440 mm. Therefore, the base area of the special layer has the dimensions SB=880 mm and SL=1020 mm.

In the stack of goods 2, which is readily packaged and formed as a packaging unit 18, the top normal layer 5.1, which consists like any other normal layer 5 of five packaging objects 4, lies on this special layer 8. These bags 4 have a length l of 650 mm and a width of 440 mm. They are placed next to one another in the way that is illustrated in FIG. 1, with three bags 4 that are adjacent to one another in the longitudinal direction and two bags 4 that are provided at the front side of said adjacent bags and that are adjacent to one another over their broadside. Hence, the normal layer 5 is spread out to base area with a width NB and a length NL of 110 and 1300 mm. In one assumingly concentrical arrangement of the lowest normal layer 5.1 and the normal layers 5 located on top of said normal layer above the special layer 8, each of the encroachment areas is formed with a cover by the first normal layer 5.1 of at least 110 mm that is located on top of said encroachment areas.

The packaging unit 18 that is formed this way is coated with different film hoods in the embodiment shown in FIG. 4 according to the theory of EP 2 036 818 A1, i.e. a holding layer 20, a first film 22 that is at first pulled over the stack of goods 2 from the lower side located at the top like the holding layer and a second film hood 24, which is formed over the stack of goods 2 that is aligned in a way that the special layer 8 comes downwards after turning of said stack of goods 2. The first and the second film material could be identical or different.

REFERENCE SIGN LIST

-   2 Stack of goods -   4 Packaging objects of the normal layer -   5 Normal layer -   6 Top side -   8 Special layer -   10 Packaging objects of the special layer -   12 Side areas -   14 First encroachment area -   16 Second encroachment area -   18 Packaging unit -   20 Holding layer -   22 First film -   24 Second film -   b Width of the packaging object of the normal layer -   l Length of the packaging object of the normal layer -   B Width of the packaging object of the special layer -   L Length of the packaging object of the special layer -   NB Width of the normal layer -   NL Length of the normal layer -   SB Width of the special layer -   SL Length of the special layer 

What is claimed:
 1. A method for producing a pallet-less packaging unit that comprises multiple packaging objects that are stacked to a stack of goods and in which the packaging objects are stacked in such a way that a special layer, which forms at least two encroachment areas for fork legs of a lift truck, is formed on at least one stack level, wherein the special layer is stacked at first to a normal layer that is larger in relation to said special layer, the stack of goods is wrapped in any case with its encroachment areas with a first film; the stack of goods that is wrapped on one side is turned around so that the part of the stack of goods that has the special layer comes downwards and that the stack of goods is wrapped with a second film that reaches up to the first film, wherein, the special layer forms two first encroachment areas for the fork legs and two second encroachment areas for the fork legs, wherein the second encroachment areas extend essentially in a rectangular way in relation to the first encroachment areas.
 2. The method according to claim 1, wherein at least some packaging units that form the special layer are smaller than the packaging units that form the normal layer.
 3. The method according to claim 2, wherein all packaging units that form the special layer are smaller than the packaging units that form the normal layer.
 4. The method according to claim 1, wherein the packaging units that form the normal layer are formed with identical sizes.
 5. The method according to claim 1, wherein the normal layer is formed with five packaging units and the special layer with four packaging units.
 6. The method according to claim 1, wherein the packaging units that form the special layer are bags with a base area whose width is 440 mm+/−30 mm and whose length is 510 mm+/−30 mm.
 7. The method according to claim 1, wherein the special layer has a base area whose width (SB) is 880 mm+/−60 mm and whose length (SL) is 1020 mm+/−60 mm.
 8. The method according to claim 1, wherein the normal layer has a base area whose width (NB) is 1100 mm+/−60 mm and whose length (NL) is 1300 mm+/−60 mm.
 9. The method according to claim 1, wherein bags with different sizes are produced and filled in a bagging facility, which stacks to bags as packaging units to a stack of goods, and fed to a palleting device via a conveying track.
 10. The method according to claim 9, wherein the palleting device stacks the bags of the normal layer and the bags of the special layer at a palleting position.
 11. The method according to claim 10, wherein the palleting device stacks the bags of the normal layer at a first palleting position and that the bags of the special layer are laid via a laying device of the special layer.
 12. The method according to claim 10, wherein the bags of the normal layer and the bags of the special layer are made of the same film material by means of a form-fill-seal method.
 13. A method for producing a pallet-less packaging unit that comprises multiple packaging objects that are stacked to a stack of goods and in which the packaging objects are stacked in such a way that a special layer, which forms at least two encroachment areas for fork legs of a lift truck, is formed on at least one stack level, wherein the special layer is stacked at first to a normal layer that is larger in relation to said special layer, the stack of goods is wrapped with its encroachment areas with a first film; the stack of goods that is wrapped on one side is turned around so that the part of the stack of goods that has the special layer comes downwards and that the stack of goods is wrapped with a second film that reaches up to the first film, wherein, the packaging units that form the special layer are bags with a base area whose width (B) is 440 mm+/−30 mm and whose length (L) is 510 mm+/−30 mm, the special layer has a base area whose width (SB) is 880 mm+/−60 mm and whose length (SL) is 1020 mm+/−60 mm, the normal layer has a base area whose width (NB) is 1100 mm+/−60 mm and whose length (NL) is 1300 mm+/−60 mm.
 14. The method according to claim 13, wherein bags with different sizes are produced and filled in a bagging facility, which stacks to bags as packaging units to a stack of goods, and fed to a palleting device via a conveying track.
 15. The method according to claim 14, wherein the palleting device stacks the bags of the normal layer and the bags of the special layer at a palleting position.
 16. The method according to claim 15, wherein the palleting device stacks the bags of the normal layer at a first palleting position and that the bags of the special layer are laid via a laying device of the special layer.
 17. The method according to claim 16, wherein the bags of the normal layer and the bags of the special layer are made of the same film material by means of a form-fill-seal method.
 18. A method for producing a pallet-less packaging unit that comprises multiple packaging objects that are stacked to a stack of goods and in which the packaging objects are stacked in such a way that a special layer, which forms at least two encroachment areas for fork legs of a lift truck, is formed on at least one stack level, wherein the special layer is stacked at first to a normal layer that is larger in relation to said special layer, the stack of goods is wrapped with its encroachment areas with a first film; the stack of goods that is wrapped on one side is turned around so that the part of the stack of goods that has the special layer comes downwards and that the stack of goods is wrapped with a second film that reaches up to the first film, wherein, all packaging units that form the special layer are smaller than the packaging units that form the normal layer.
 19. The method according to claim 18, wherein the packaging units that form the normal layer are formed with identical sizes. 